1. Field of the Invention
This invention relates to mounting frames for holding glazings such as windows in structures, and more particularly to the snap lock vision frame assemblies in fire-rated structures such as doors and walls.
2. Description of the Related Art
The installation of vision frame assemblies in doors, especially of the fire-rated variety, has often been a difficult and time-consuming process. Prior art frame assemblies are often constructed of several parts that must be separately manufactured and inventoried. FIG. 1 illustrates a portion of such an assembly 10 installed in a cutout 12 of a wooden fire-rated door 14. The frame assembly 10 includes a front frame member 16 connected to a rear frame member 18 by a series of screws 20 arranged around the perimeter of the frame assembly 10. Each frame member 16, 18 includes an outer flange 22 connected to an inner flange 24 by a captive edge 26. The outer flange 22 has a first vertically oriented panel 28 that abuts a vertical surface 30 of the door 14 adjacent the cutout 12 and a second panel 32 that extends obliquely from the first panel 28 to the captive edge 26. The outer flange 22 of the rear frame member also includes apertures 31 for receiving the screws 20. The inner flange 24 of each frame member has a first vertically oriented panel 34 that extends from the captive edge 26 to a step portion 36. The step portion 36 extends generally horizontally to a vertically-oriented mounting lip 38. Each mounting lip 38 has an aperture for receiving the screw 20. When assembled, the panels 34 face each other to create a pocket 40 that receives a peripheral edge portion of a window pane or glazing 42 and glazing tape 44 located on opposite sizes of the glazing 42.
During installation, the front frame member 16 must be manually held in place while a layer of glazing tape 44, the glazing 42, another layer of glazing tape 44, and the rear frame member 18 are installed. Accordingly, installation can be quite awkward and can require much time and skill. Moreover, the finished product is neither entirely aesthetically pleasing nor secure, since the screw heads are exposed on the rear frame member. In addition, the front and rear frame members are not identical and therefore require a separate manufacturing operations. Separate inventories must be kept for each of the frame members, screws, and different thicknesses of tapes due to tolerance variations in the door and glazing thicknesses.
For hollow fire-rated doors 46 as shown in FIG. 2, the same frame assembly 10 can be used with the addition of reinforcing clips 48 installed at various locations around a cutout 50 in the door 46 to strengthen the door cutout. As seen in FIG. 3, the reinforcing clip 48 has a plate portion 52 with mounting lips 54, 56 extending from opposite ends of the plate portion, and an intermediate lip 57 extending between the opposite ends and generally transverse to the mounting lips 54, 56. When installed, the reinforcing clips 48 hold a front metallic skin 58 and a rear metallic skin 60 against a hollow core material 62. In addition to the disadvantages described with respect to wooden doors, the reinforcing clips require additional manufacturing, inventory, and increased installation time.
Another prior art clip 64 for mounting in hollow door cutouts is illustrated in FIG. 4. The clip 64 has a plate portion 66 with mounting lips 68, 70 extending from opposite ends of the plate portion. A first tab 72 is mounted adjacent the lip 70 and a second tab 74 is mounted adjacent the lip 68. The tabs 72, 74 extend generally transverse to the lips 68 and are formed at diagonally opposite corners of the plate portion 66. A first spring finger 76 has a first end adjacent the lip 70 and a second free end that projects toward the lip 68. Likewise, a second spring finger 78 has a first end adjacent the lip 68 and a second free end that projects toward the lip 70. Each spring finger 76, 78 has a stepped portion 80 that together form a channel for receiving the peripheral edge portion of a window pane and frame members. Although this prior art clip possesses some advantages over other prior art arrangements, it is not, inter alia, adaptable to tolerance variations in the door, window pane, and glazing tape thicknesses, as well as variations in glazing space between the frames. Moreover, the clip 64 is not universal for both solid and hollow doors.